title: New cryogenic phase transitions in SrSnO3.
abstract: Strontium stannate is under study as an ultra-stable dielectric material for microelectronic applications at low temperatures. It is known to have a remarkably temperature-independent dielectric constant from 27 K to room temperature. However, we report anomalies in the Raman spectra, dielectric response, and differential thermal analysis of strontium stannate compatible with a structural phase transition at 160 K. Further anomalies are seen in calorimetric and Raman data (but not dielectric data) that suggest another phase transition at 270 K. A preliminary x-ray powder diffraction study confirms a small change in the pseudo-cubic lattice constant a(T) at the lower transition.
authors.affiliation: Center of Material Science, University of Allahabad, Allahabad 211002, India.
authors.forename: Manoj K
authors.initials: MK
authors.lastname: Singh
authors.forename: J W
authors.initials: JW
authors.lastname: Hong
authors.forename: N K
authors.initials: NK
authors.lastname: Karan
authors.forename: Hyun M
authors.initials: HM
authors.lastname: Jang
authors.forename: R S
authors.initials: RS
authors.lastname: Katiyar
authors.forename: S A T
authors.initials: SA
authors.lastname: Redfern
authors.forename: J F
authors.initials: JF
authors.lastname: Scott